There is an interesting article in a resent issue of Practical Fishkeeper about keeping tropical fish in an unheated tank. A variety of readily available, coolwater adaptable fish, in addition to white clouds, were discussed. They included dojos, various danios and barbs as well as corydorus. Other suggested fish included hillstream loaches. It was a good article that could give those of us that keep hillstream loaches other suggestions for tank mates.